C# Bug in WebRequest

I have discovered what I believe is a bug in the C# framework.

I have a simple code that sends a Http webdav request

req = (HttpWebRequest)WebRequest.Create(url);
  
req.Method = « PROPFIND »;
  
req.Headers = new WebHeaderCollection();
  
// I dunno what’s for, but Sharepoint throws error 404 if it is not set
  
req.Headers.Set(« translate », « f »);
  
req.Headers.Set(« Depth », depth.ToString());

// encode en UTF8 le corp de message à transmettre
  
byte[] bytes = Encoding.UTF8.GetBytes((string)query);

req.ContentType = « text/xml »;
  
req.ContentLength = bytes.LongLength;

RequestStream = req.GetRequestStream();
  
RequestStream.Write(bytes, 0, bytes.Length);
  
RequestStream.Close();
  
HttpWebResponse webResp = (HttpWebResponse)req.GetResponse();
  
// Note : C# has no constant for http status code WEBDAV_MULTI
  
if (((int)webResp.StatusCode) == 207)
      
{
   
// handle web response
       
}

Everything works fine most of the time.

This is a typical http dump

`
PROPFIND /path/to/foo.bar HTTP/1.1
translate: f
Depth: 0
Content-Type: text/xml
Host: httpserver
Content-Length: 90
Expect: 100-continue
HTTP/1.1 100 Continue
< ?xml version=”1.0” encoding=”UTF-8”?>HTTP/1.1 207 Multi-Status
Date: Mon, 27 Dec 2010 09:42:27 GMT
Server: IBM_HTTP_Server/2.0.47.1 Apache/2.0.47 (Unix) DAV/2
Transfer-Encoding: chunked
Content-Type: text/xml; charset=”utf-8”</p>

37b
< ?xml version="1.0" encoding="utf-8"?>
<d:multistatus xmlns: D="DAV:" xmlns:ns0="DAV:">

/path/to/foo.bar



2010-12-21T15:07:41Z
2269
Tue, 21 Dec 2010 15:07:41 GMT
"4cc6-8dd-ff786940"
F












HTTP/1.1 200 OK


</d:multistatus>
` Now, sometimes, C# hangs on `
PROPFIND /path/to/foo.bar HTTP/1.1
translate: f
Depth: 0
Content-Type: text/xml
Host: httpserver
Content-Length: 90
Expect: 100-continue
HTTP/1.1 100 Continue
` It is only 100 seconds afterwards that the IBM http server sends a timeout. Why is the request never send? [Mironelli gives a workaround](http://haacked.com/archive/2004/05/15/http-web-request-expect-100-continue.aspx#1908) ``` req.ServicePoint.Expect100Continue = false; ``` That way, the request contains the full body from the beginning, instead of [a check for the server capabilities](http://www.w3.org/Protocols/rfc2616/rfc2616-sec8.html#sec8.2.3).